Food trucks have soared in popularity for two very simple reasons: They allow entrepreneurial operators a relatively low-cost, small-staff way of launching a business, and they can instantly transform a food desert into a lunchtime hot spot. But are traditional eateries losing customers to this proliferation of meals-on-wheels?

Researchers spoke to people who had purchased food from a truck, asking them where they would have gotten their meals had there been no truck. Half of the respondents said they would probably have just eaten fast food, while another 20% said they would likely have just skipped the meal.

This would seem to imply that places like McDonald’s and Burger King are the big losers in the food truck wars, and that may be true. But it’s not that the food trucks are necessarily cheaper or more convenient. More than likely, lunch at a food truck costs a little more than the McD’s value menu, and ordering often requires the customer to stand in line outside while a kitchen of 2-3 people tend to all the customers.

The draw, customers tell NPD, is that the food is simply more interesting at food trucks. American consumers all know what a fast food burger tastes like (or have made the choice to never find out), so even fans of quick-service restaurant chains still want the occasional change-up. This explains why an impressive 61% of the food trucks in the NPD survey served some form of Mexican food.

But while the trucks provide a welcome change to the fast food rut, the survey found that most people are not swapping out one habit for another and replacing Big Macs with Korean BBQ cheesesteaks or PB&J sliders. Instead, the food trucks are often occasional treats that consumers give themselves. That plays right into the mobility aspect of the food truck business; if people in one neighborhood get tired of eating your food every day, just move elsewhere.

So it seems like food trucks aren’t yet killing off Ronald McDonald, but the upstart industry does have some tricks it can teach the old dogs of fast food.

“[I]n markets with a developed food truck presence, QSR operators may wish to take note of the benefits food trucks offer, such as different and fresh food, especially as a means to build their snack business and/or protect lunch traffic,” explains Bonnie Riggs, NPD restaurant industry analyst.